THE BASAL GANGLIA: Neuroanatomy S. J. Potashner sjp9713@neuron.uchc.edu

FUNCTIONS Facilitates the most effective motor, emotional and cognitive behavior for the prevailing circumstances, and suppresses other behaviors. (Action selection) Motor: Facilitates actions with positive outcomes. Binds sequences of such actions into behavior units. Such units are bound together in sequence into longer, more complex behaviors. Put Parkinson’s & Huntington’s here as examples. Describe symptoms.

SIGNALING SCHEME - - Cerebral cortex Basal Ganglia + emotions many areas upper motor neurons cognitive Thalamus - Basal Ganglia + - 3 neural pathways Brain stem pre-motor neurons output

Substantia Innominata COMPONENTS BASAL GANGLIA Caudate Putamen Globus Pallidus ……… Substantia Innominata Nucleus Basalis Nucleus Accumbens Olfactory Tubercle Striatum (non-primate) Dorsal Ventral ASSOCIATED NUCLEI Subthalamic Nucleus Substantia Nigra

NEUROANATOMY A B D C

INPUT PATHWAYS TO THE STRIATUM Frontal Eye Field Dorso-lat Prefrontal Ctx Post Parietal Ctx Lat Orbito-frontal Ctx Ant Cingulate Ctx Ant Temporal Ctx Parietal Eye Field Amygdala Prim Motor Ctx Supp & Pre-motor Ctx Prim Somatosensory Ctx Para-hippocampal Ctx Temporal Ctx Visual Assoc Ctx Auditory Assoc Ctx Putamen Association Ctx Motor or Sensory Ctx

STRIATAL ANATOMY Caudate Striosomes Striosome reticulum Matrix Putamen

STRIATAL ANATOMY Association Ctx (layers IIII-V) Limbic & Other (deep layer V) Somatosensory Ctx Motor Ctx Substantia Nigra compacta Direct pathway (action selection) Striosome Indirect pathway (action suppression) Matrix Medium spiny neurons Cholinergic interneurons Dopaminergic axons

PATHWAYS THROUGH THE BASAL GANGLIA

BASAL GANGLIA OUTPUT PATHWAYS Lenticular fasciculus Thalamic fasciculus Thalamus Ansa lenticularis

BASAL GANGLIA OUTPUT PATHWAYS SC SN

SEGREGATED PATHWAYS ACA ant cingulate area; APA arcuate premotor area; CAUD b body, h head; DLC dorsolat prefrontal ctx; EC entorhinal ctx; FEF frontal eye fields; HC hippocampal ctx; ITQ Inf temporal gyrus; LOF lat orbitofrontal ctx; MC motor ctx; MD medial dorsal thalamus; PPC post parietal ctx; PUT putamen; SC somatosensory ctx; SMA suppelmentary motor ctx; STQ sup tempotal gyrus; VA ventral anterior thalamus; VL ventral lateral thalamus; VP ventral pallidum; VS ventral striatum; cl caudolateral; cdm caudal dorsomedial; l lateral; ldm lateral dorsomedial; m medial; mdm medial dorsomedial;; pm posteromedial; rd rostrodorsal; rl rostrolateral; rm rostromedial; vm ventromedial; vl ventrolateral.